RESUMEN
INTRODUCTION: Treatment of rectal cancer requires a multidisciplinary approach with standardized surgical, pathological and radiotherapeutic procedures. Sphincter preserving surgery for cancer of the lower rectum needs a long-course of neoadjuvant treatments to reduce tumor volume, to induce down-staging that increases circumferential resection margin, and to facilitate surgery. AIM: To evaluate the rate of anal sphincter preservation in low lying, resectable, locally advanced rectal cancer and the resectability rate in unresectable cases after neoadjuvent chemoradiation by oral Capecitabine. PATIENTS AND METHODS: This trial included 43 patients with low lying (4-7 cm from anal verge) locally advanced rectal cancer, of which 33 were resectable. All patients received preoperative concurrent chemoradiation (45 Gy/25 fractions over 5 weeks with oral capecitabine 825 mg/m2 twice daily on radiotherapy days), followed after 4-6 weeks by total mesorectal excision technique. RESULTS: Preoperative chemoradiation resulted in a complete pathologic response in 4 patients (9.3%; 95% CI 3-23.1) and an overall downstaging in 32 patients (74.4%; 95% CI 58.5-85). Sphincter sparing surgical procedures were done in 20 out of 43 patients (46.5%; 95% CI 31.5-62.2). The majority (75%) were of clinical T3 disease. Toxicity was moderate and required no treatment interruption. Grade II anemia occurred in 4 patients (9.3%, 95% CI 3-23.1), leucopenia in 2 patients (4.7%, 95% CI 0.8-17) and radiation dermatitis in 4 patients (9.3%, 95% CI 3-23.1) respectively. CONCLUSION: In patients with low lying, locally advanced rectal cancer, preoperative chemoradiation using oral capecitabine 825 mg/m2, twice a day on radiotherapy days, was tolerable and effective in downstaging and resulted in 46.5% anal sphincter preservation rate.